A Brief History of the Development of the Periodic Table

By peter.gooley

  • Chemical elements arranged

    Alexandre-Emile Beguyer de Chancourtois publishes a paper that arranges the chemical elements in order of atomic weights. However, he does this in terms of geology so is primarily ignored by chemists.

  • Periodic table organized

    Julius Lothar Meyer proposes a theory that chemical elements can be organized such that it is divided into equal groups with similar properties.

  • Periodic table suggested

    John Newlands sorts elements into a periodic table based on their mass.

  • Periodic table created

    Dmitri Mendeleev creates a periodic table, leaving space for unknown elements.

  • Argon discovered

    William Ramsay discovers the existence of the noble gas argon.

  • Neon, krypton and radon discovered

    William Ramsay discovers the existence of neon, krypton and radon.

  • Cause of radioactivity discovered

    Ernest Rutherford discovers that radioactivity is caused by the breakdown of atoms.

  • Protons identified

    Ernest Rutherford uses his knowledge of positive and negative rays to determine the existence of protons.

  • Atomic numbers proposed

    Henry Moseley suggested using the number of protons in an element rather than the atomic mass for identification and identified several gaps in the periodic table.

  • Lanthanides and actinides identified

    Glenn Seaborg identifies the lanthanide and actinide element families.